Crude Oil as an Input Cost to Refiners

It is true to say that the cost of crude oil is the major input cost for refiners. However, the relationship between such a cost and the final price for a petroleum product produced from that crude, such as petrol or diesel, is not as direct as one would think.
There are, for instance, additional petroleum product markers which give a guide to prices. That is, prices are not just a function of cost-push, but are also strongly influenced by demand-pull.
For example, USA environmental requirements for gasoline (petrol) have at times pushed up the prices in the USA by significantly more than the movements in crude prices. This is the market working as refiners who see these prices work hard to increase production to capture some of these high prices before they dissipate under competitive pressure – both from within the USA and from the resulting massive influx of product cargoes from other producing centers in the world.
There are also a number of other variables which affect the price of products such as petrol. In addition the perception of the purchasers and sellers in the market as to the price risk over time can also add or subtract premiums to the product marker price.